This is why I tell people that MMA/boxing/muay thai and the like arent the "end all be all" to unarmed self defense. Don't get me wrong, MMA training is great and helps to build good skills and attributes but it also conditions the trainee with bad muscle memory in many cases.
Example: After training boxing 3x a week for a little over a year I got into an unarmed fight against a bigger guy who was both drunk and on drugs while at a party (I was young and still partied back then). I have him three solid straight rights to the face and he ate them like they were nothing. Why did I punch him? Thats what I was conditioned to do and we fight like we train.
We ended up in a clinch and somehow I ended up poking him in his eye extremly well. He was done after that. I added in Krav Maga (thankfully I found a legit instructor) and found a Kelly McCann "Kembatives" style group and started training in that a lot more than boxing.
Boxing gave me a good base but all the unamed fights ive been in since while working security I believe the krav and kelly mccann stuff came in more handy.
That said, the best unarmed style is to extend your arm and pick up a weapon.
Just my .02 cents.